There is a significant problem with existing methods of manufacture of alkanolamides and the by-products formed thereby. It has been found that by-products are prone to form throughout the reaction process. A particularly significant impurity, bis-hydroxyethyl piperazine (BHEP), is formed via dimerisation of two DEA molecules. BHEP crystallizes out of the composition, particularly if present in concentrations of over 5000 ppm, though lower concentrations may also be problematic in some circumstances. Crystallisation of BHEP out of the composition may result in an end user perceiving problems with the composition as deposits of BHEP appearing in, for example, barrels of the composition would give the appearance of a contaminated or faulty batch, even if there would be no deleterious effects of the BHEP in use. Thus the effects of significant BHEP presence in an alkanolamide composition make it an undesirable constituent.
Accordingly, it is desirable to provide improved methods of production of such an alkanolamide, which contain a reduced amount of undesirable reaction by-products, particularly BHEP.